1. Field of the Invention
The present invention relates to a seal grommet feeder of a seal processing station of a harness making machine.
2. Description of the Related Art
A seal processing station of a harness making machine is described in International application WO 9708787. In this application a seal processing station for a harness making machine is shown comprising a seal sorting and feeding unit that feeds single wire seal grommets on a feed track which carries the seal grommets to an insertion device. The insertion device positions the seal grommets over the end of an electrical or optical wire for the purpose of sealing the wire end, which may be terminated to a terminal, in a connector housing. The feed track is mounted on a vibrator unit, which vibrates so that the grommets are fed from the seal sorting unit to the insertion device along the feed track. The feed track has a groove within which a narrow portion of the grommet is received so that the central axis of the grommet (i.e., the axis at the center of the hole extending through the grommet) is substantially perpendicular to the direction of the feed track. Single wire grommets typically have one or more radial sealing lips of a greater diameter than the narrow portion received in the groove of the feed track.
In order to position the grommets on the vibrating feed track, such that the smaller end inserts into the groove of the feed track and the grommet is oriented with its axis of a rotation perpendicular to the feed track direction, grommets are randomly dropped on the vibrating feed track whereby some grommets fall off, some grommets orient themselves correctly in the groove of the feed track and others remain on the feed track incorrectly oriented. In order to feed only correctly oriented grommets on the feed track at or proximate the exit of the feed track from the seal sorting unit, a jet of air is blown across the feed track through a nozzle arranged adjacent the feed track above the groove. The jet of air blows off incorrectly oriented grommets.
The air pressure of the nozzle must be finely tuned in order to ensure that the air pressure is sufficient to blow off all incorrectly oriented grommets, but not any correctly oriented grommets. The sensitivity of adjustment increases with grommet shapes that are xe2x80x9ctop-heavyxe2x80x9d.
The inventor of the present invention described hereinafter, realized that the problem of blowing correctly oriented seals off the feed track increases with higher feed rates, and may even become the limiting factor in reducing cycle times of harness making machines.
Accordingly, it is an object of the present invention to provide a reliable grommet feeding device that can operate at high speed and with a variety of different grommet designs, some of which may be particularly top heavy.
Pursuant to this object, and others which will become apparent hereafter, one aspect of the present invention resides in a seal grommet feeding device for feeding seal grommets having a substantially axisymmetric shape extending along a center axis between first and second ends, the feeding device comprising a feed track having a groove for receiving the first end of the grommet therein. The device further comprises an air propulsion member that blows a jet of air across the feed track for removing incorrectly oriented seal grommets off the feed track. Substantially at the position of the air jet with respect to the direction along the feed tack, the device comprises a retention shoulder against which the second end of the seal grommet abuts. The retention shoulder is positioned above the feed track with a spacing sufficient to allow passage of incorrectly oriented seal grommets therethrough. Thus, correctly oriented grommets, even particularly top heavy ones, are not blown off the feed track due to engagement of the upper ends thereof against the retention shoulder, whereas incorrectly oriented seal grommets are blown through the spacing beneath the retention shoulder. The air propulsion device may comprise a nozzle provided in an extension of one side wall of the feed track. The nozzle may be positioned between the top of the feed track groove and the retention shoulder such that the air jet blows into the space therebetween.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.